Most research on long chain methyl ketones has focused on their origins and distributions. Their application in paleoclimate studies is less common than that of other n-alkyl lipids. The goal of this research was to explore this potential by studying n-alkan-2-ones from the Hani peat sequence in northeastern China. They were identified using gas chromatography–mass spectrometry (GC–MS) and showed a distribution ranging from C19 to C31 with a strong odd/even predominance. This type of distribution is considered to derive from Sphagum and microbial oxidation of n-alkanes. Comparison with climate sensitive indicators and macrofossil analysis shows that microbial oxidation of n-alkanes derived from higher plants was enhanced during the warm early Holocene period. This led us to develop three n-alkan-2-one proxies – C27/RC23–31 (C27/HMW-KET), carbon preference index (CPIH-KET) and average chain length (ACL(27–31)-KET) – as possible indicators of paleoclimate in the peat-forming environment. These proxies, in combination with C27 n-alkane dD values and peat cellulose d18O records, might allow examination of paleo-ecosystem behavior during climatic evolution in northeastern China over the past 16,000 yr.